Loosing oil and coolant

[Essexmiles]

Hi,

I have a 140 A3 TDI 56 plate and yesterday the oil light poped up so pulled over and topped it up and thought nothing of it as I know these cars can burn a little oil (or so I'm told). Misses goes to use car this morning and low coolant light comes on straight away so got her to top it up a little. But now I'm worried there could be an issue with head gasket or turbo seals (these turbos water cooled and oil cooled like the mk4s?)

Only had the car since November and done about 4k init and oil level was fine (if I remember correctly it was between min and max) then but don't no about coolant but any coolant lose is a worry.

would these be linked or just a coincidence that the cars burned a bit of oil and come to the min point the same time as a coolant leak has sprung.

Car has done 100k miles now and just wondered if there's any check or tests I can do myself to rule out possible faults or if there's any common leak points like oil cooler ect. Misses is at work with the car at the moment so can't give it a look over till she's back. also oil was fine in filler cap and dipstick, no May ect

cheers

 

[JJ.Foulds]

i got told, to check oil cap for excess 'mayo' looking gunk at top. Means excess moisture in oil system.

and also to check coolant bottle for any impurities that may be floating on top when i thought my gasket was gone. Oil getting into coolant.

Im sure someone will come up with a proper answer tho, but there are kits to check if any gasses are in the coolant also.

 

[Essexmiles]

Oil looked spot on when I checked yesterday, no gunk or mayo ect but I will double check later if it stops ******* it down. Might remove belly pan and leave some cardboard under the car over night and see if there's any leaks over night.

Cheers

 

[SmithyAG]

Turbo is not water cooled so won't be that losing coolant.
Common coolant leaks on these are porous cylinder head, EGR cooler, corner of radiator corroded and leaking.
Oil loss could be a simple leak or as you have said a more serious issue with head gasket etc.
Is there any smoke on hard acceleration? - Blue(ish) smoke on full throttle can be turbo oil seal.
Smoke on start up? - White smoke on start up could be head gasket leaking coolant into cylinders, blue could be head gasket leaking oil into cylinders.

If only losing fluids whilst being driven (coolant system under pressure) it could be the porous head issue, although I would have expected it to have surfaced and been dealt with by 100k miles.

 

[Essexmiles]

Turbo is not water cooled so won't be that losing coolant.
Common coolant leaks on these are porous cylinder head, EGR cooler, corner of radiator corroded and leaking.
Oil loss could be a simple leak or as you have said a more serious issue with head gasket etc.
Is there any smoke on hard acceleration? - Blue(ish) smoke on full throttle can be turbo oil seal.
Smoke on start up? - White smoke on start up could be head gasket leaking coolant into cylinders, blue could be head gasket leaking oil into cylinders.

If only losing fluids whilst being driven (coolant system under pressure) it could be the porous head issue, although I would have expected it to have surfaced and been dealt with by 100k miles.

Just had a look over the car and water pump is working fine, no smoke when revving in neutral and haven't noticed any when under load but would be hard to notice due to tailpipes pointing to floor but the oil loss isn't a major worry as it's only about a cup full over at least 4k miles and I was under the impression these do burn oil? Please correct me if I'm wrong though.

Noticed the the egr valve looked like it had been leaking a bit, there was black oily dirt where the pipe goes onto the little vessel on the egr valve on the inlet manifold (new to diesels so I may have these parts named wrong) would this just be a vacuum leak wrong the hose causing this? Not really sure how these work. Going to jack car up and take bottom panel of and see if I can see any coolant leaks. Is the EGR cooler easier to inspect from undernieth or is it best to remove air box and battery ect? (Guessing that's the area it's in but will double check online).

also noticed oily residue on the rocker breather hose that goes onto the tip? Unclipped the pipe and there's oil in there bits it's not gunked up or anything so guessing this is nothing to worry about.

My main concern is the coolant leak and I'll keep an eye on the level for a while as not sure at the moment how quickly it is dropping. I'd hope a porous head would of shown up by now especially with full audi service history.

cheers

 

[SmithyAG]

A cup full of oil missing over 4k miles I wouldn't worry about. Some of these engines never want for any oil between services, some do. Mine varies, generally needing one top up between services of a few 100ml.

The EGR valve leaking is most likely the diaphragm in the valve leaking, when it can't hold vacuum any more you will get an engine management light on. Best was to test it is to remove from the car and use a hand held vacuum pump to see if the valve is operational and holding vacuum. (You can do it on the car to see if it holds vac but won't be able to see the action of the valve.) Replacements are about £65 from Andrew Page (where i got mine from), and are OEM - they are wahler or pierburg and have the VW stamp still on them!

Oil on the breather hose from rocker cover is probably from it not being clicked on properly, this is where excess crankcase pressure is vented, so oil in this is perfectly normal provided it is just oil and not gunky (which you said yours isn't).

You are bang on with EGR cooler location, its awkward. Removal is probably easiest with a mixture of above and below the car. Removing it is probably easiest way to inspect it. You need to look inside it to see where the exhaust gas flows and
check for any crystallization/crusty coolant marks. Excellent guide to everything EGR related here How To: EGR Valve / EGR Cooler Delete Mk5 TDI (BKD / BMN) - Guides - TDISport
including photos and diagrams of whats what and how to remove them.

Hopefully when you get under the car you may have a better idea of where the coolant leak is!

 

[Essexmiles]

A cup full of oil missing over 4k miles I wouldn't worry about. Some of these engines never want for any oil between services, some do. Mine varies, generally needing one top up between services of a few 100ml.

The EGR valve leaking is most likely the diaphragm in the valve leaking, when it can't hold vacuum any more you will get an engine management light on. Best was to test it is to remove from the car and use a hand held vacuum pump to see if the valve is operational and holding vacuum. (You can do it on the car to see if it holds vac but won't be able to see the action of the valve.) Replacements are about £65 from Andrew Page (where i got mine from), and are OEM - they are wahler or pierburg and have the VW stamp still on them!

Oil on the breather hose from rocker cover is probably from it not being clicked on properly, this is where excess crankcase pressure is vented, so oil in this is perfectly normal provided it is just oil and not gunky (which you said yours isn't).

You are bang on with EGR cooler location, its awkward. Removal is probably easiest with a mixture of above and below the car. Removing it is probably easiest way to inspect it. You need to look inside it to see where the exhaust gas flows and
check for any crystallization/crusty coolant marks. Excellent guide to everything EGR related here How To: EGR Valve / EGR Cooler Delete Mk5 TDI (BKD / BMN) - Guides - TDISport
including photos and diagrams of whats what and how to remove them.

Hopefully when you get under the car you may have a better idea of where the coolant leak is!

Cheers mate that thread was a good read. Hopefully it's the cooler leaking. Any reason you replaced the egr valve and didn't just delete it? If my coolers leaking I think I'll be deleting the whole lot. I'll have to do a bit more reading to make sure there's no possible problems caused by deleting it.

cheers

 

[SmithyAG]

I had only just got the car and was finding my way round it, so not knowing the risks/benefits of deleting the EGR and the fact a new valve was cheaper than a delete pipe made it a no brainer at the time.

I'm actually toying with the idea of doing the delete now. Have a look through my posting history, there's a thread about pros and cons somewhere!

 

[Essexmiles]

I had only just got the car and was finding my way round it, so not knowing the risks/benefits of deleting the EGR and the fact a new valve was cheaper than a delete pipe made it a no brainer at the time.

I'm actually toying with the idea of doing the delete now. Have a look through my posting history, there's a thread about pros and cons somewhere!

Having a look around there doesn't really seem to be any cons from what I've read. Even if my coolers not leaking I think after all the reading I've done I'll be doing this delete anyways.